Paper towel



Dec. 27, 1966 G. w WYANT 3,293,683

PAPER TOWEL Filed Jan. 4, 1965 FIG- 2 I N VEN TOR.

GER/4L D 144 WVflA/T ATTORNEY United States Patent F 3,293,683 PAPERTOWEL Gerald W. Wyant, Montreal, Quebec, Canada, assignor to Union OilCompany of California, Los Angeles, Calif, a corporation of CaliforniaFiled Jan. 4, 1965, Ser. No. 423,120 6 Claims. (Cl. 15-506) Thisapplication is a continuation-in-part of my copending application,Serial No. 193,614, filed May 1962 now abandoned, and relates to a novelpaper towel structure particularly adapted to use in cleaning glasssurfaces such as windows and automobile Windshields. More particularly,it relates to la two-ply paper towel in which each ply is adapted toperform a separate and distinct function.

At the present time, in automobile service stations, it is commonpractice in cleaning Windshields to spray an aqueous detergent solutionon the glass surface and then wipe oif the moisture and loosened dirtwith a paper or cloth towel. If a particularly good job is desired, itis usually necessary to give thesurface a final polishing with a drytowel. As is well known such practice is far from satisfactory, both tothe customer and the service station attendant. If too much of thedetergent solution is employed, eiher the windshield is streaked orhazed with the excess detergent or it must be flushed with clean waterand extra towels used for wiping and polishing. If too little of thedetergent is used, the windshield is not satisfactorily cleaned and theentire job must be repeated. Moreover, in either event, the operation istime-consuming and uneconomical in that it involves the purchase,storing, dispensing, and manipulation of several materials.

It is accordingly the primary object of the present invention to provideimproved means for cleaning windshields, windows, and similar smoothsurfaces, which means consists in a unitary article of manufacturecomprising a detergent material, means for applying the same to a wettedsurface, and means for subsequently drying and polishing the surface.This and related objects and their attendant advantages are achieved inthe paper towel structure described in detail below and shown in theaccompanying drawing which forms a part of this application. In saiddrawing, FIGURE 1 represents a plan view of one embodiment of theinvention; FIGURE 2 represents an enlarged cross-sectional view of thestructure of FIGURE 1; FIGURE 3 represents a plan view of anotherembodiment of the invention; and FIGURE 4 represents a cross-sectionalview of still another embodiment.

Considering now the invention in detaihthe subject matter thereofconsists in a two-ply paper towel structure, one ply of which(hereinafter referred to as the first ply) is composed of a fibrousmaterial which tends to undergo some degree of physical deteriorationupon contact with a wet surface and has a controlled amount of adetergent material applied to its outer surface, and the other ply ofwhich (hereinafer referred to as the second ply) is substantially freeof detergent material and is composed of a different fibrous materialwhich has high water absorption capacity and is substantially resistantto physical deterioration upon contact with a wet surface. In use, thesurface to be cleaned is first wetted with water, the latter beingsuitably applied in the form of a fine spray dispensed from the familiarsqueeze bottle or the like.

3,293,683 Patented Dec. 27, 1966 ICC The wetted surface is then scouredwith the towel, with the dettergent-bearing side of the first ply beingapplied to the wetted surface so that the detergent dissolves in thewater to form a cleansing foam which loosens the dirt adhering to thesurface. In addition, since the first ply is composed of a materialwhich tends to disintegrate in contact with water, it will form a thinsponge-like pad which will serve further to loosen the dirt bymechanical abrasion. When the surface has been thoroughly scoured withthe first ply, the towel is turned over and the surface is wiped dry andclean with the second ply. As stated, the latter is highly absorptivewith respect to Water and i has high wet strength; consequently, itserves to absorb all of the dirty foam and to polish the surface tocomplete cleanliness.

As will be apparent from the foregoing, the separate plies of thepresent towel have separate and distinctly different functions. Thefirst ply serves (a) to apply the detergent material to the surfacewhich is to be cleaned, and (b) to form a mildly abrasive scouring pad.The second ply serves (a) to pick up loosened solid dirt and dirty foam,and (b) to polish the surface to a high gloss. Since such functions areto a considerable extent mutually exclusive, it follows that the essenceof the invention lies in constructing the plies from different types ofmaterial. As is more fully pointed out hereinafter, a second essen tialfeature lies in carefully controlling the manner and amount in which thedetergent material is applied to the outer surface of the first ply.

Turning now to suitable materials of construction for the respectiveplies, the first ply may consist of any fibrous material which tends todisintegrate upon contact with a wet surface. A high degree of waterabsorbency is not essential since it is the function of the second plyto absorb water and dry the surface being cleaned. Any of a wide varietyof animal or vegetable fibers, felted or otherwise provided in sheetform, may be employed but it is preferred to use a paper stockcontaining a substantial proportion, e. g., 30 percent or more ofgroundwood. The rough texture of the latter provides the desiredabrasive action, and its short fiber length insures the desired tendencyto disintegrate upon contact with water. Excellent results are obtainedwith a paper stock consisting of about 55-65. percent of bleached kraitor sulfite pulp and about 35-45 percent of groundwood. Conventionalnewsprint stock may likewise be employed. Because of the requirementwith respect to disintegration, sizing is contraindicated. Also sincethe two plies function independently of one another, the first plyshould be substantially imperforate in order to prevent the second plyfrom becoming wet While scouring with the first ply side of the towel.

The second ply is suitably constructed of high wetstrength paper towelstock or, more economically, of kraft pulp or even a mixture of knafttpulp and groundwood. In the latter instance, however, the groundwoodcontent should not exceed about 25 percent; otherwise, the second plywill not have sufiicient wet-strength. A stock consisting of abutpercent kraft pulp and about 20 percent groundwood will give verysatisfactory results combined with maximum economy, whereas bleachedkraft or sulfite pulp which has been chemically treated (as withureaformaldehyde or melamine-formaldehyde resins) to provide maximumwet-strength may be employed for higher quality, but more expensive,products. Since it is essential that the second ply have highwater-absorption capacity, sizin thereof is recluded.

The detergent material which is applied to the outer surface of thefirst p-ly may be any of the wide variety of materials known to havedetergent properties. Ordinary soaps, i-.e., the alkali=metal salts offatty acids of vegetable or animal origin may be employed, b ut itispreferred to use one or more of the many so-called syntheticdetergents, particularly the alkyl aryl sulfonates, the longchain alkylsulfates, water-soluble petroleum sulfonates, and sulfonat'edglycerides. A wide variety of such materials is available commerciallyunder such trademarks as Naccanol, Ultrawet, lj'reft, Petronate,Santomer'se, etc. A preferred class of detergent materials constitutesthe sulfonated alkyl benzenes and sulfonated alkylnaphthalenes in whichthe alkyl group contains about l 18 carbon atoms, e.g., sodiumdodecylbenzene sulfonate, sodium oleylnaphthalene sulfonate, etc.

As previously stated, it is important that careful control must 'beexerted with respect to the amount of detergent employed. Too littledetergent will of course fail to provide adequate cleansing, whereas toomuch will form suds or foam in amounts which exceed the obsorptioncapacity of the second ply. In general, the amount of detergent appliedto the first ply should not exceed about 0.08, nor be less than about0.05, gram per square foot. I have found in order to achieve adequatecontrol of the amount of detergent, it is necessary that the latter beapplied to the outer surface of the'first ply, as opposed toimpregnating the entire sheet. I have further found that the detergentis most suita'bly applied to a plurality of discrete areas of thesurface of the first ply (as opposed to a continuous coating) and thatsuch application is most suitably carried out by a printing techniquewhereby the first ply is continuously passed over or under a printingroller which is inked with a solution of detergent and is embossed toproduce the desired pattern of detergent. The latter is applied to theembossed roller in the form of a solution or paste formed by dissolvingor dispensing the detergent in a suitable carrier liquid. Ethyleneglycol and similar viscous liquids are preferred as carrier liquids. Theconcentration of detergent in the carrier liquid will depend upon theidentity of the two, as well as upon the amount of detergent to beapplied and the proportion of the towel area which is to be covered.Very satisfactory results have been obtained by printing the first plywith a 50 percent solution of Nacconol NRSF (a sodium alkaryl sulfonatedetergent manufactured by the National Aniline and Chemical Co.) inethylene glycol, with the printing roller being so embossed as to applysuch solution in the form of uniformly spaced squares whose total areaequals about percent of the total area of the ply being printed. Wherethe towel is to be used in localities where the water supply isrelatively alkaline, it is desirable to incorporate a small amount,e.g., 0.02 to 2 percent, of a buffering agent such as citric acid in theprinting solution or paste.

Upon completion of the printing operation, the printed ply is dried andre-rolled, preferably in contact with the second ply so as to form thetwo-ply structure in a Single operation. If it is desired to dispensethe towel in roll form, the structure may be perforated during there-rolling operation so that suitably sized towels can be readily tornfrom the roll by the ultimate consumer. Alternatively, the re-rolledstructure may be cut into individual towels which are then interfoldedand packaged for loading into a conventional dispensing cabinet.

In order that the user may distinguish between the two plies, it isdesirable that they be formed from stocks of different color.Alternatively, the detergent may be colored so as to present a coloredpattern on the first ply and thereby identify the same on the correctside of the towel to be applied to the wetted surface.

Referring now to FIGURES 1 and 2 of the drawing,

there is shown first and second plies 10 and 12, respec tively, with thedetergent material being carried on the outer surface of first ply 10 inthe form of narrow stripes 14. The structure has @been cut to theindicated length in a zig-Zag pattern 16 which assists in keeping thetwo plies aligned and prevents them from readily becoming separated.FIGURE 3 shows a similar structure, with the detergent being applied tothe outer surface of first ply 18 in the form of uniformly-spacedsquares 20 covering about 5 percent of the total area. FIGURE 4 shows astructure similar to that of FIGURE 3 except that the plies have beenlightly embossed for the purpose of increasing their adherence to eachother and providing increased abrasive properties.

Tabulated below are typical specifications for a paper towel structureconstructed in accordance with the invention and particularly adaptedfor use in cleaning automobile Windshields.

Unbleached kral't, percent. Bleached kratt, percent. Detergent, gm./sq.it, Area coverage, percent Other modes of applying the principle of myinvention may be employed instead of those explained, change being madeas regards the materials or steps employed, provided the article ofmanufacture defined by the following claims, or the equivalent thereof,be claimed.

I therefore particularly point out and distinctly claim as my invention:

1. A cleaning towel comprising first and second adherent sheetssuperimposed to form a two-ply structure, said first sheet beingsubstantially imperforate and composed of a fibrous material which tendsto undergo physical deterioration upon contact with a wet surface andhaving a detergent material applied to the outer surface thereof, andsaid second sheet being substantially free of detergent material andconsisting of a fibrous material having high water absorption capacityand being substantially resistant to physical deterioration upon contactwith a wet surface.

2. A cleaning towel as defined by claim 1 wherein said first sheet iscomposed of paper containing at least about 30 percent of groundwood.

3. A cleaning towel as defined by claim 1 wherein said second sheet iscomposed of kraft pulp containing from 0 to about 25 percent ofgroundwood.

4. A cleaning towel as defined by claim 1 wherein said detergent isapplied to a plurality of discrete, substantially uiiiformly spacedareas of the outer surface of said first P y- 5. A cleaning towelcomprising first and second adherent sheets superimposed to form atwo-ply structure, said first ply being composed of an unsized paperpulp containing at least about 30 percent of groundwood and having adetergent applied to a plurality of discrete substantially uniformlyspaced areas of the outer surface thereof, and said second ply beingcomposed of an unsized kraft pulp containing less than about 25 percentof groundwood.

6. A cleaning towel comprising first and second sheets superimposed toform a two-ply structure, said first ply being composed of an unsizedpaper pulp consisting of between about 35 and about 45 percent ofgroundwood and between about 55 and about 65 percent of a pulp selectedfrom the group consisting of bleached kraft pulp 5 and bleached sulfitepulp, and having an alkyl aryl sulfonate detergent applied to aplurality of discrete substantially uniformly spaced areas of the outersurface thereof in an amount corresponding to between about 0.05 andabout 0. 08 gram per square foot of said surface, and said second plybeing composed of an unsized paper pulp consisting of about 20 percentgroundwood and about 80 percent of unbleached kraft pulp, and oppositeedges of said two-ply structure being serrated to assist in main-References Cited by the Examiner UNITED STATES PATENTS taining saidplies aligned and to prevent them from readily 10 CHARLES WILLMUTHPfima'y Examine"- R. L. BLEUTGE, Assistant Examiner.

becoming separated.

1. A CLEANING TOWEL COMPRISING FIRST AND SECOND ADHERENT SHEETSSUPERIMPOSED TO FORM A TWO-PLY STRUCTURE, SAID FIRST SHEET BEINGSUBSTANTIALLY IMPERFORATE AND COMPOSED OF A FIBROUS MATERIAL WHICH TENDSTO UNDERGO PHYSICCAL DETERIORATION UPON CONTACT WITH A WET SURFACE ANDHAVING A DETERGENT MATERIAL APPLIED TO THE OUTER SURFACE THEREOF, ANDSAID SECOND SHEET BEING SUBSTANTIALLY FREE OF DETERGENT MATERIAL ANDCONSISTING OF A FIBROUS MATERIAL HAVING HIGH WATER ABSORPTION CAPACITYAND BEING SUBSTANTIALLY RESISTANT TO PHYSICAL DETERIORATION UPON CONTACTWITH A WET SURFACE.